MacViews: Protect against orderOut: on an NSWindow with an attached sheet.

ui/views/widget/native_widget_mac_unittest.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ui/views/widget/native_widget_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #import "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
@@ skipping 1027 matching lines @@
     EXPECT_FALSE(hide_waiter.method_called());
 
     // Wait for the hide again. It will call close on its retained copy of the
     // child NSWindow, but that's fine since all the C++ objects are detached.
     hide_waiter.WaitForMethod();
     EXPECT_TRUE(hide_waiter.method_called());
   }
 }
 
 // Tests behavior of window-modal dialogs, displayed as sheets.
-// Disabled: fails due to sharding adjustments. DCHECK fails during closure when
-// the parent window receives an asynchronous occlusion state change from the
-// window server, after the child has its parent window relationship removed.
-// TODO(tapted): Fix it. http://cbrug.com/666503.
-TEST_F(NativeWidgetMacTest, DISABLED_WindowModalSheet) {
+TEST_F(NativeWidgetMacTest, WindowModalSheet) {
   NSWindow* native_parent =
       MakeNativeParentWithStyle(NSClosableWindowMask | NSTitledWindowMask);
 
   Widget* sheet_widget = views::DialogDelegate::CreateDialogWidget(
       new ModalDialogDelegate(ui::MODAL_TYPE_WINDOW), nullptr,
       [native_parent contentView]);
 
+  WidgetChangeObserver widget_observer(sheet_widget);
+
   // Retain, to run checks after the Widget is torn down.
   base::scoped_nsobject<NSWindow> sheet_window(
       [sheet_widget->GetNativeWindow() retain]);
 
   // Although there is no titlebar displayed, sheets need NSTitledWindowMask in
   // order to properly engage window-modal behavior in AppKit.
   EXPECT_EQ(NSTitledWindowMask, [sheet_window styleMask]);
 
   sheet_widget->SetBounds(gfx::Rect(50, 50, 200, 150));
   EXPECT_FALSE(sheet_widget->IsVisible());
@@ skipping 18 matching lines @@
                 *did_observe_ptr = true;
               }];
 
   sheet_widget->Show();  // Should run the above block, then animate the sheet.
   EXPECT_TRUE(did_observe);
   [[NSNotificationCenter defaultCenter] removeObserver:observer];
 
   // Modal, so the close button in the parent window should get disabled.
   EXPECT_FALSE([parent_close_button isEnabled]);
 
+  // The sheet should be hidden and shown in step with the parent.
+  widget_observer.WaitForVisibleCounts(1, 0);
+  EXPECT_TRUE(sheet_widget->IsVisible());
+
+  // TODO(tapted): Ideally [native_parent orderOut:nil] would also work here.
+  // But it does not. AppKit's childWindow management breaks down after an
+  // -orderOut: (see BridgedNativeWidget::OnVisibilityChanged()). For regular
+  // child windows, BridgedNativeWidget fixes the behavior with its own
+  // management. However, it can't do that for sheets without encountering
+  // http://crbug.com/605098 and http://crbug.com/667602. -[NSApp hide:] makes
+  // the NSWindow hidden in a different way, which does not break like
+  // -orderOut: does. Which is good, because a user can always do -[NSApp
+  // hide:], e.g., with Cmd+h, and that needs to work correctly.
+  [NSApp hide:nil];
+
+  widget_observer.WaitForVisibleCounts(1, 1);
+  EXPECT_FALSE(sheet_widget->IsVisible());
+  [native_parent makeKeyAndOrderFront:nil];
+  widget_observer.WaitForVisibleCounts(2, 1);
+  EXPECT_TRUE(sheet_widget->IsVisible());
+
   // Trigger the close. Don't use CloseNow, since that tears down the UI before
   // the close sheet animation gets a chance to run (so it's banned).
   sheet_widget->Close();
   EXPECT_TRUE(sheet_widget->IsVisible());
 
   did_observe = false;
 
   // Experimentally (on 10.10), this notification is posted from within the
   // -[NSWindow orderOut:] call that is triggered from -[ViewsNSWindowDelegate
   // sheetDidEnd:]. |sheet_widget| will be destroyed next, so it's still safe to
   // use in the block. However, since the orderOut just happened, it's not very
   // interesting.
   observer = [[NSNotificationCenter defaultCenter]
       addObserverForName:NSWindowDidEndSheetNotification
                   object:native_parent
                    queue:nil
               usingBlock:^(NSNotification* note) {
                 EXPECT_TRUE([sheet_window delegate]);
                 *did_observe_ptr = true;
               }];
 
   // Pump in order to trigger -[NSWindow endSheet:..], which will block while
   // the animation runs, then delete |sheet_widget|.
-  TestWidgetObserver widget_observer(sheet_widget);
   EXPECT_TRUE([sheet_window delegate]);
   base::RunLoop().RunUntilIdle();
   EXPECT_FALSE([sheet_window delegate]);
 
   EXPECT_TRUE(did_observe);  // Also ensures the Close() actually uses sheets.
   [[NSNotificationCenter defaultCenter] removeObserver:observer];
 
   EXPECT_TRUE(widget_observer.widget_closed());
   EXPECT_TRUE([parent_close_button isEnabled]);
 }
@@ skipping 703 matching lines @@
 
 - (void)dealloc {
   if (deallocFlag_) {
     DCHECK(!*deallocFlag_);
     *deallocFlag_ = true;
   }
   [super dealloc];
 }
 
 @end